From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33574) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzjOe-0008P2-G8 for qemu-devel@nongnu.org; Wed, 25 Jun 2014 05:21:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WzjOY-0002U5-Ay for qemu-devel@nongnu.org; Wed, 25 Jun 2014 05:21:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55450) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzjOY-0002Ty-2H for qemu-devel@nongnu.org; Wed, 25 Jun 2014 05:21:34 -0400 Date: Wed, 25 Jun 2014 12:21:41 +0300 From: "Michael S. Tsirkin" Message-ID: <20140625092141.GL32652@redhat.com> References: <1403662641-28526-1-git-send-email-tiejun.chen@intel.com> <1403662641-28526-3-git-send-email-tiejun.chen@intel.com> <20140625064545.GB25563@redhat.com> <53AA8404.8040708@intel.com> <20140625082850.GB32652@redhat.com> <53AA8AAB.30100@intel.com> <20140625084347.GE32652@redhat.com> <53AA8CC2.7090406@intel.com> <20140625090420.GG32652@redhat.com> <53AA92F6.1090803@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53AA92F6.1090803@intel.com> Subject: Re: [Qemu-devel] [v5][PATCH 2/5] xen, gfx passthrough: create pseudo intel isa bridge List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Chen, Tiejun" Cc: peter.maydell@linaro.org, xen-devel@lists.xensource.com, stefano.stabellini@eu.citrix.com, allen.m.kay@intel.com, qemu-devel@nongnu.org, Kelly.Zytaruk@amd.com, yang.z.zhang@intel.com, anthony@codemonkey.ws, anthony.perard@citrix.com, pbonzini@redhat.com On Wed, Jun 25, 2014 at 05:14:30PM +0800, Chen, Tiejun wrote: > On 2014/6/25 17:04, Michael S. Tsirkin wrote: > >On Wed, Jun 25, 2014 at 04:48:02PM +0800, Chen, Tiejun wrote: > >>On 2014/6/25 16:43, Michael S. Tsirkin wrote: > >>>On Wed, Jun 25, 2014 at 04:39:07PM +0800, Chen, Tiejun wrote: > >>>>>In fact it's exactly what passthrough does. > >>>>>I wonder if more bits from ./hw/i386/kvm/pci-assign.c > >>>>>can be reused. How do you poke at the host device? sysfs? > >>>> > >>>>Yes, sysfs. > >>>> > >>>>Thanks > >>>>Tiejun > >>> > >>>Then you should be able to re-use large chunks of > >>>./hw/i386/kvm/pci-assign.c: basically everything > >>>that deals with emulation. > >> > >>Do you mean those hooks to get info from the real device? Xen have its own > >>wrapper, xen_host_pci_get_block(), so we always go there in xen scenario. > >> > >>Thanks > >>Tiejun > > > >Yes and that's not good. We have two pieces of code doing mostly > >identical things slightly differently. > >hw/i386/kvm/pci-assign.c is a bit younger so it's cleaner, > >but these really need to be unified. > > > > Sorry, take a look at this again, > > xen_host_pci_get_block(XenHostPCIDevice *d, int pos, uint8_t *buf, int len) > | > + xen_host_pci_config_read(d, pos, buf, len) > | > + pread(d->config_fd, buf, len, pos) > > I thinks this should be same as kvm. > > Thanks > Tiejun get_block is trivial. I really mean the whole PT infrastructure for - discovering host devices through sysfs - virtualizing devices rom, bars, msi ... the list goes on. logic is mostly the same. -- MST